A glassy carbon electrode modified by a copolymer of Co-tetrakis (para-aminophenyl)porphyrin and ortho-phenylenediamine. Characterization and electrocatalytic sulfite oxidation behavior of a basic extract from red wine

• Published in: Journal of applied electrochemistry 2014-12, Vol.44 (12), p.1361-1369
• Main Authors: Arce, Roxana, Romero, Julio, Aguirre, María J.
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Copolymers; Electrochemistry; Electrodes; Glassy; Glassy carbon; Industrial Chemistry/Chemical Engineering; Oxidation; Physical Chemistry; Research Article; Sulfites; Wines
• ISSN: 0021-891X; 1572-8838
• DOI: 10.1007/s10800-014-0750-7

In this work, we present a comparison among three glassy carbon electrodes modified by Co-porphyrin, ortho-phenylenediamine, or both simultaneously. This comparison shows the differences among the electrochemical behavior, morphological characteristics and electrocatalytic behavior toward the sulfite oxidation of these electrodes. The electrode modified by Co-porphyrin, ortho-phenylenediamine and copolymer has been investigated in detail for the comparision of electrocatalytic activity towards the sulfite oxidation. In the case of the glassy carbon-modified electrodes, the presence of the copolymer enhances the electrocatalytic performance of the modified electrodes in spite of the non-catalytic response (compared to the bare glassy carbon) of both homopolymer-modified electrodes toward the oxidation of sulfite. Additionally, the oxidation of sulfite extracted from red wine is shown. The copolymer-modified electrode is capable of oxidizing the extracted free sulfite in a 0.02 M NaOH solution. Through the addition of standards method, a concentration of free sulfite in a Chilean red wine sample was determined to be 44 ppm.